Polar Bears Play-fight during mating season (http://en.wikipedia.org/wiki/File:Polar_Bears_Play_fight.JPG)
Introduction
Polar bears, latin name Ursus maritimus are usually cute, with thick white fur to most people. However, they are the largest member in the Ursus family and also the largest carnivore in the world. Adult male polar bears can weigh between 350 and 680 kg, while adult female polar bears are about half of that size They live in the northern Arctic and spend part of their lifetime at sea or offshore pack ice, along the coasts. They are excellent swimmers that they are able to swim 100 miles away from land or ice. The polar bear is classified as a vulnerable species because of the unrestircted hunting and drowning for swimming too long because of the melting of ice due to the global warming.
Scientific Classification
Kingdon
Animalia
Phylum
Chordata
Class
Mammlia
Order
Carnivora
Family
Ursidae
Genus
Ursus
Species
U. maritimus
Habitat
a worldwide distribution of polar bears in winter (grey area) (http://www.kidzone.ws/sg/polarbear/polar_bear.htm)
As everyone knows, the polar bear habitat encompasses the entire Arctic region. Nowadays, most polar bears live on the islands in the northern arctic region, and over forty percent polar bear live in the northern Canada, espicially near Churchill in Manitoba where it is a rich biological productivity area.
Polar bears are able to swim in water and live on land. Therefore, their habitat is pack ice along the coasts, where the ice connects with water, which allows them to swim and hunt for food. Polar bears do not stay in one certain place, they always migrate in order to look for food. However, the bears prefer the ice packs than areas like inland beacause the ice packs allow them remain close contact with their main food source, Seals and also walruses.
Polar bears are very active along the coast as mentioned. They like to walk on ice packs and look for food. Since ice packs are like floating the the water, it is very convinient for the polar bears to go swimming and diving when they want to. Another habitat of polar bears is water. Thery spend most of their time under water to find other food sources other than seals.
For various reasons, part of the polar bears spend most of their year on land. For example polar bears living in a warmer climate or in summer, they may be stranded on land because the ice along the coast is melted and the floating sea ice, pack ice may shift to the north. Other than that, pregnant female polar bears spend half of the year on land in maternity dens.
ice pack is polar bear's main habitat (http://2.bp.blogspot.com/_EqQZrgoXvqM/R3P0wlDukzI/AAAAAAAABHg/aP8TNM-7Njs/s400/Ice%2Bfloe.jpg)
Adaptations
Structural Adaptation 1
One very obvious structural adaptation that polar bears have is their thick fur and skin. Compare to other members in the bear family or even their closest
relative, the brown bear and grizzly bear, polar bears are very unique, they have adapted the frigid weather and have thick white fur and black skin underneath. Polar bears' tans actually ain't white. Their fur consist of two layers, one is a dense underfur and other is a outer layer of guard hairs, which is actually transparent. Their fur allows them to keep themselves warm under the frigid weather, it also acts as an barrier between their skin and the water to protect polar bears from the freezing water and also the the brutal wind. Polar bear's 'white' fur can also used as a protective color and protect them from their enemies in the Arctic where everything is bright and white, for example when baby polar bear is born, the mother polar bear can hide them safely and protect from being eaten by other polar bears. Other than that, polar bears' black skin has the similar functions as their fur. Their skin allows them to receive as much heat as possible form the sun to keep them warm.
2
Polar bears are excellent swimmers. They are able to swim six miles per hour and a polar bear have been recorded swimming for as far as 320 km from land. The reason of why polar bears are excellent swimmers is because they have webbed feet and large forepaws to help them swim. Polar bears' webbed feet can distribute the pressure when they walk on snow or think ice and provide propulsion when swimming. Their feet are very large and they may measure thirty cm across. Besides their feet, the pads on polar bears' paws can increase the traction on the ice and prevent them from slipping. Also, the thickly callused paws can protect them from the cold and prevent polar bears being cut by sharp ice edge, it can also act as an deadly weapon to fight against other polar bears or attack their food sources, like catch the seals out of water.
Behavior Adaptation 1
Unlike most of the bears, polar bears don't usually attack other or human unless they are extremely hungry or being attacked by them. When facing other polar bears or enemies, they usually choose to escape rather than start a fight. They rarely attack people especially fat polar bears unless they provoke them. Besides, comparing with brown bears, polar bears seem to be more 'humane'. Brown bears usually maul a person then they would walk away. Whereas, polar bears' attack are often fatal and more likely to be predatory. They are more likely to attack their food source and the attacks are quick and fatal. Also as mentioned, they seldom raid human and since the population of human in the Arctic is small, this cases are very rare. So, difference from what people think, polar bears ain't fierce, they wouldn't attack human unless we provoke them.
Behavior Adaptation 2
As mentioned, polar bears do not stay in one certain place. They are always moving to different places in order to look for food sources, seals and also find a better living environment. Due to the change in weather from season to season that influence their sea ice habitat, polar bears would move to difference directions. In summer, polar bears would move northwards when the ice melt and a continuous southward ice drift. While during autumn, polar bears would move southward due to the sea ice advance. Polar bears can travel upon thirty km per day, they remain staying in one certain place during a season and would move to another location when the season changes. Therefore, it means that polar bear's distribution is partly due to the cliamte changes
Physiological Adaptation
Living in a frigid place, polar bear must have to keep themselves warm so that their organism wouldn't be frozen by the cold weather. They have adapted the freezing environment, hence they are warm blooded animal. The main reason why they are warm-blooded is because it helps polar bears to regulate and maintain their body temperature at a same level. As they are warm-blooded animals, their bodies know how to operate themselves to cool down and produce heat. Under the cold weather, people may think polar bears' bodies need to produce more heat anytime. However, that is wrong. Since polar bears are so well inlustrated by their skin and fur, they tend to overheat easily when they run. As they can be overheat easily, polar bears like to rest when they are not hunting fo food.
Etruscan bear (fossil animal)/ Aquatic bear (future animal)
Introduction
Polar bears, latin name Ursus maritimus are usually cute, with thick white fur to most people. However, they are the largest member in the Ursus family and also the largest carnivore in the world. Adult male polar bears can weigh between 350 and 680 kg, while adult female polar bears are about half of that size They live in the northern Arctic and spend part of their lifetime at sea or offshore pack ice, along the coasts. They are excellent swimmers that they are able to swim 100 miles away from land or ice. The polar bear is classified as a vulnerable species because of the unrestircted hunting and drowning for swimming too long because of the melting of ice due to the global warming.Scientific Classification
Kingdon
Animalia
Phylum
Chordata
Class
Mammlia
Order
Carnivora
Family
Ursidae
Genus
Ursus
Species
Habitat
Polar bears are able to swim in water and live on land. Therefore, their habitat is pack ice along the coasts, where the ice connects with water, which allows them to swim and hunt for food. Polar bears do not stay in one certain place, they always migrate in order to look for food. However, the bears prefer the ice packs than areas like inland beacause the ice packs allow them remain close contact with their main food source, Seals and also walruses.
Polar bears are very active along the coast as mentioned. They like to walk on ice packs and look for food. Since ice packs are like floating the the water, it is very convinient for the polar bears to go swimming and diving when they want to. Another habitat of polar bears is water. Thery spend most of their time under water to find other food sources other than seals.
For various reasons, part of the polar bears spend most of their year on land. For example polar bears living in a warmer climate or in summer, they may be stranded on land because the ice along the coast is melted and the floating sea ice, pack ice may shift to the north. Other than that, pregnant female polar bears spend half of the year on land in maternity dens.
Adaptations
Structural Adaptation 1
One very obvious structural adaptation that polar bears have is their thick fur and skin. Compare to other members in the bear family or even their closest
relative, the brown bear and grizzly bear, polar bears are very unique, they have adapted the frigid weather and have thick white fur and black skin underneath. Polar bears' tans actually ain't white. Their fur consist of two layers, one is a dense underfur and other is a outer layer of guard hairs, which is actually transparent. Their fur allows them to keep themselves warm under the frigid weather, it also acts as an barrier between their skin and the water to protect polar bears from the freezing water and also the the brutal wind. Polar bear's 'white' fur can also used as a protective color and protect them from their enemies in the Arctic where everything is bright and white, for example when baby polar bear is born, the mother polar bear can hide them safely and protect from being eaten by other polar bears. Other than that, polar bears' black skin has the similar functions as their fur. Their skin allows them to receive as much heat as possible form the sun to keep them warm.
Structural Adaptation
Polar bears are excellent swimmers. They are able to swim six miles per hour and a polar bear have been recorded swimming for as far as 320 km from land. The reason of why polar bears are excellent swimmers is because they have webbed feet and large forepaws to help them swim. Polar bears' webbed feet can distribute the pressure when they walk on snow or think ice and provide propulsion when swimming. Their feet are very large and they may measure thirty cm across. Besides their feet, the pads on polar bears' paws can increase the traction on the ice and prevent them from slipping. Also, the thickly callused paws can protect them from the cold and prevent polar bears being cut by sharp ice edge, it can also act as an deadly weapon to fight against other polar bears or attack their food sources, like catch the seals out of water.
Behavior Adaptation 1
Unlike most of the bears, polar bears don't usually attack other or human unless they are extremely hungry or being attacked by them. When facing other polar bears or enemies, they usually choose to escape rather than start a fight. They rarely attack people especially fat polar bears unless they provoke them. Besides, comparing with brown bears, polar bears seem to be more 'humane'. Brown bears usually maul a person then they would walk away. Whereas, polar bears' attack are often fatal and more likely to be predatory. They are more likely to attack their food source and the attacks are quick and fatal. Also as mentioned, they seldom raid human and since the population of human in the Arctic is small, this cases are very rare. So, difference from what people think, polar bears ain't fierce, they wouldn't attack human unless we provoke them.
Behavior Adaptation 2
As mentioned, polar bears do not stay in one certain place. They are always moving to different places in order to look for food sources, seals and also find a better living environment. Due to the change in weather from season to season that influence their sea ice habitat, polar bears would move to difference directions. In summer, polar bears would move northwards when the ice melt and a continuous southward ice drift. While during autumn, polar bears would move southward due to the sea ice advance. Polar bears can travel upon thirty km per day, they remain staying in one certain place during a season and would move to another location when the season changes. Therefore, it means that polar bear's distribution is partly due to the cliamte changes
Physiological Adaptation
Living in a frigid place, polar bear must have to keep themselves warm so that their organism wouldn't be frozen by the cold weather. They have adapted the freezing environment, hence they are warm blooded animal. The main reason why they are warm-blooded is because it helps polar bears to regulate and maintain their body temperature at a same level. As they are warm-blooded animals, their bodies know how to operate themselves to cool down and produce heat. Under the cold weather, people may think polar bears' bodies need to produce more heat anytime. However, that is wrong. Since polar bears are so well inlustrated by their skin and fur, they tend to overheat easily when they run. As they can be overheat easily, polar bears like to rest when they are not hunting fo food.
References/Bibliography